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AB
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AB∠EFB+∠AFE=180°,CD∠EFB=∠D.
AB
BE
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; △BEFE △BEDF,
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CD
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C D
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1.B; 2.C; 3.A; 4.95°.
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-
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BC=AE=AC+CE=DE+CE.
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BC∥DE,#$∠BCE=∠E.!"△ABC
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EC=BF,
AC=AF,
AE=AB
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#$ △EAC
≌△BAF(SSS).#$ ∠C=∠F.8)92:5,;
∠ANF=∠CNM.#$180°-∠C-∠CNM =180°-
∠F-∠ANF,.∠CMF=∠NAF.
6.
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BC,
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6 △ABC7 △DCB0,
AB=DC,
AC=DB,
BC=CB
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∠D,∠ABC=∠DCB,∠ACB=∠DBC.#$ ∠ABC-
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7.C.
12.2.2
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5.
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AB∥DE,#$∠A=∠D.!"AF=DC,
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AF-CF=DC-CF,
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AC=DF.
6 △ABC7
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AC=DF